build: Add more options to autogen.sh.

* autogen.sh: Add options --print-host and --print-build.
--

Being able to know the build system and the host as used by GnuPG is
useful to build other packages.

autogen.sh

@@ -70,6 +70,8 @@ MSGMERGE=${GETTEXT_PREFIX}${MSGMERGE:-msgmerge}${GETTEXT_SUFFIX}
 DIE=no
 FORCE=
 SILENT=
+PRINT_HOST=no
+PRINT_BUILD=no
 tmp=$(dirname "$0")
 tsdir=$(cd "${tmp}"; pwd)
 version_parts=3
@@ -89,6 +91,14 @@ if test x"$1" = x"--force"; then
   FORCE=" --force"
   shift
 fi
+if test x"$1" = x"--print-host"; then
+  PRINT_HOST=yes
+  shift
+fi
+if test x"$1" = x"--print-build"; then
+  PRINT_BUILD=yes
+  shift
+fi
 
 
 # Reject unsafe characters in $HOME, $tsdir and cwd.  We consider spaces
@@ -229,16 +239,22 @@ fi
 # **** end FIND VERSION ****
 
 
-# ******************
-#  W32 build script
-# ******************
-if [ "$myhost" = "w32" ]; then
 if [ ! -f "$tsdir/build-aux/config.guess" ]; then
     fatal "$tsdir/build-aux/config.guess not found"
     exit 1
 fi
 build=`$tsdir/build-aux/config.guess`
+if [ $PRINT_BUILD = yes ]; then
+    echo "$build"
+    exit 0
+fi
 
+
+
+# ******************
+#  W32 build script
+# ******************
+if [ "$myhost" = "w32" ]; then
     case $myhostsub in
         ce)
           w32root="$w32ce_root"
@@ -279,6 +295,10 @@ if [ "$myhost" = "w32" ]; then
         fi
         die_p
     fi
+    if [ $PRINT_HOST = yes ]; then
+        echo "$host"
+        exit 0
+    fi
 
     if [ -f "$tsdir/config.log" ]; then
         if ! head $tsdir/config.log | grep "$host" >/dev/null; then
@@ -299,13 +319,6 @@ fi
 # ***** AMD64 cross build script *******
 # Used to cross-compile for AMD64 (for testing)
 if [ "$myhost" = "amd64" ]; then
-    shift
-    if [ ! -f $tsdir/build-aux/config.guess ]; then
-        echo "$tsdir/build-aux/config.guess not found" >&2
-        exit 1
-    fi
-    build=`$tsdir/build-aux/config.guess`
-
     [ -z "$amd64root" ] && amd64root="$HOME/amd64root"
     info "Using $amd64root as standard install directory"
     replace_sysroot
@@ -326,6 +339,10 @@ if [ "$myhost" = "amd64" ]; then
         echo "Stop." >&2
         exit 1
     fi
+    if [ $PRINT_HOST = yes ]; then
+        echo "$host"
+        exit 0
+    fi
 
     if [ -f "$tsdir/config.log" ]; then
         if ! head $tsdir/config.log | grep "$host" >/dev/null; then